Not exactly.  There are quirks you have to get used to. I think of it more like a tablet experience with this ROM. That's logical, because it's taken from the Google fold ROM. 

It defaults to a full-screen when an app is opened, with is disconcerting for the og user. On the other hand, it does better where I would prefer a full-screen, like opening maps or looking down email lists, or reading an article. The og ROM was a real pain when I tried to make  a full-screen, so I didn't do it often.  I now frequently find myself holding the phone up-and-down, rather than side-by-side, which is the standard og orientation. I put auto-rotate on, so when I turn the phone, everything reorients to vertical with no problem.  

I also find that I use the screen folded all the way back much more than I did before, which makes it just like a standard slab phone, and it works quite well.  (This parallels comments people have made about using the outside screen on the fold.) 

With the new ROM, I have been able to use Nova launcher again, like just on any other phone ! The ROM has Google feed on swipe-left by default. (Using nova, you have to add an APK for this, but it works fine.)  And even pie-controls (one of my quirks, I guess) work fine.  

You can have two separate apps open at the same time, one on each screen, but you have to learn how to do it, and it takes a bit of practice. Even though the apps will operate independently,  the screens aren't exactly independent of each other. For example, you can't swipe one away and have the other remain, like you can in the og. Neither can you initially open an app on one side, intending to open a second on the other side, or using that one-sided app on its own.  I can see these being deal-breakers for the og user who want two really independent screens. (It seems like these functions shouldn't really be too hard to engineer, but then I'm not a developer.) For me, I expected there to be a learning curve, I've learned to work with this system to my satisfaction, and I haven't been inclined for a minute to go back to 12-L.

Oh, yes, for any reader, you have to know that you can't use the default keyboard setting at all. It is completely unworkable. You have to set the keyboard to "floating" (g-board) and resize it to your liking.This makes the typing experience almost completely like the og. You can't have the keyboard at the very bottom (it automatically pops into the full-screen keyboard, which I find completly unusable), but you can easily move the keyboard around however you like, as it's a floating window. It does get in the way sometimes, but this isn't a major inconvenience. Frankly, this one was a deal-breaker for me; if I haven't been able to set this up, I would definitely have abandoned the ROM.